Regional anesthesia and pain medicine
-
Reg Anesth Pain Med · Jul 2008
Interactions between pulmonary performance and movement-evoked pain in the immediate postsurgical period: implications for perioperative research and treatment.
Previous data suggest that movement-evoked pain is more closely correlated with pulmonary performance than rest pain beyond 24 hours following lower abdominal surgery. Because adverse alterations in lung physiology are initiated intraoperatively and impact upon pulmonary morbidity, this study tests the hypothesis that movement-evoked pain correlates negatively with pulmonary performance in the immediate postoperative period. ⋯ Considering these and previous results, pulmonary function tests such as PEF should be considered for more routine use as functional surrogates of movement-evoked pain in analgesic trials of thoracic and abdominal surgery. Mechanisms of immediate postoperative movement-evoked pain may differ from those in effect at later time points after which tissue inflammation and spinal sensitization develop. Because pain adversely impacts upon postoperative rehabilitation, these results further imply that aggressive treatment of movement-evoked pain could improve the outcome of postoperative rehabilitation measures if both are implemented very early after surgery.
-
Reg Anesth Pain Med · Jul 2008
Ultrasound-guided midthigh sciatic nerve block-a clinical and anatomical study.
Ultrasound-guided sciatic nerve block is a relatively new regional anesthesia technique with few descriptions in the literature. The objective of this study was to assess the ease with which the sciatic nerve could be imaged in the midthigh region using ultrasound and to describe the anatomy surrounding the sciatic nerve at this location. ⋯ Ultrasonic identification of the sciatic nerve at the midthigh level can be achieved; however, in this study, 37.5% of patients required nerve stimulation to confirm its sonographic appearance. Target nerve localization and the subsequent performance of the sciatic nerve block may be enhanced by recognition of surrounding muscular and fascial structures which were also identified using ultrasound.
-
Reg Anesth Pain Med · Jul 2008
Stereospecific interaction of bupivacaine enantiomers with lipid membranes.
S(-)-Bupivacaine has the pharmacotoxicological advantage over its antipode and racemate. The interaction with lipid membranes was compared between S(-)-, R(+)- and racemic bupivacaine. ⋯ Bupivacaine stereostructure-specifically interacts with membranes containing cholesterol, which is consistent with the clinical features of S(-)-bupivacaine. Membrane cholesterol appears to increase the chirality of lipid bilayers and enable them to interact with S(-)-, racemic and R(+)-bupivacaine differently.
-
Reg Anesth Pain Med · Jul 2008
Intraneural catheterization of the sciatic nerve in humans: a pilot study.
Imaging studies in humans have shown that intraneural injection of local anesthetic may be relatively frequent. The incidence of intraneural catheterization is unknown. We speculated that early neural blockade after the injection of a small dose of local anesthetic might be a common finding produced by unintended intraneural catheterization. We investigated the clinical effect of a small dose of local anesthetic injected through a stimulating sciatic catheter, and also the placement of the tip of the catheters by computed tomography (CT) scan. ⋯ Intraneural catheterization of the sciatic nerve may be a frequent finding and was not followed by nerve injury under the conditions of our small pilot study.
-
Reg Anesth Pain Med · Jul 2008
The sensitivity of motor response to needle nerve stimulation during ultrasound guided interscalene catheter placement.
Neurostimulation during single shot interscalene block has a significant false negative motor response rate. Compared with tangential needle approaches for single shot block, interscalene catheter (ISC) placement commonly involves Tuohy needles inserted longitudinally to the brachial plexus. This study aimed to determine the sensitivity of neurostimulation during ultrasound-guided ISC needle placement, and the feasibility of an ultrasound-guided ISC needle endpoint. ⋯ This study suggests that the false negative motor response rate for longitudinal ISC needle placement is higher than the false negative response rate associated with tangential needle approach interscalene block. An ultrasound guided ISC needle endpoint is a feasible alternative to a neurostimulation endpoint.